Utpal Dey

Mandarin Orange: Phytophthora Species: Gummosis Utpal Dey

The highest disease incidence and severity noticed in Nanded district. The disease severity was increased in the month of June and it is highest in the month of September when the temperature ranged between 18-38.5oC, humidity between 31-91% and rainfall intensity ranged between 1.5-27.5 mm with 3-6 rainy days. The heavy and more number of rains in July to September helped in spreading of disease through run off and rain splashes and at the same time, conductive temperatures and humidity conditions stimulated the development of gummosis and hence increased severity. Though day temperatures remains conductive for most part of the year in different districts of Marathwada, night temperature and slight drizzles play important role in disease development. Slight drizzles provide free water for entry of pathogen through natural openings or injuries. Bioagent Trichoderma harzianum found most effective against both species. Botanical Lantana found effective. Among all fungicides tested Dimethomorph was found most effective against both the Phytophthora spp.